Machine knitting

ABSTRACT

Lateral contraction or &#39;&#39;&#39;&#39;necking&#39;&#39;&#39;&#39; of warp-knitted tubular fabric between knitting and winding locations is prevented by inserted guide plates equal in width to the as-knit tubular portions and supported for lateral movement, as is especially useful in manufacture of panty hose and similar bifurcated tubular garment fabrics or the like.

United States Patent [72] Inventor CharlesA.Titone Burlington, NJ. (21]AppLNo. 821,922 [22] Filed MayS, 1969 [45] Patented Mar.23, 1971 [73]Assignee Titone Research & Developmen Corporation Burlington, NJ.

541 MACHINE KNITTlNG l7 Claims,6Drawing Figs;

52 'u.s.ci.....' 66/150, 66/152 [51] lnLCl. ..D04b 27/34 [50]FieldoiSearch 66/147- [56] References Cited UNITED STATES PATENTS1,770,925 7/1930 Howe 223/75X 2.407.397 9/ 1946 Carhart 66/149 2,423,4847/1947 Cosgro 66/ 147 2,434,782 l/l948 Alexander et al.. 66/1472,967,414 [/1961 Krause 66/ l 50 FOREIGN PATENTS 846,885 8/1952 Germany66/152 394,831 7/1933 Great Britain 66/ l 49 OTHER REFERENCES RaschelSeamless Tights: New Machine Developed; Hosiery Trade Journal, Vol. 74,No. 888, pages 1 16, 1 17; Dec. 1967.

Primary Examiner-Mervin Stein Attorney-Mc Clure & MillmanPATEVNTEDI'MRZSIHYI SHEET g of 2 x m a wnU m w 7%. A MINA uyw LMACHINEKNITTING This invention relates to machine knitting of tubularfabrics in flat configuration, as on a Raschel or similar warp-knittingmachine having two parallel needlebeds.

Warp knitting of tubular fabrics has been known for quite a few yearsbut generally has not been able to compete with circular knittingthereof. While the edges existing along two warp-knit panels of fabric,which are being knitted together simultaneously to complete a tube offabric, usually are supposed to be indistinguishable in the completedtubular configuration there are numerous reasons {why suchindistinguishability is difficult to accomplish. One such reason isuneven tensioning at the edges, as compared with intermediate portionsof the fabric panels, as the completed tube is withdrawn in as-kn itfiat form from between the needlebeds. Although gripped evenly betweensuitablerollers along its entire width at a winding location, whichobviously must be spaced somewhat from the knitting location, the fabriccontracts laterallyor necks" inward at its edges between the twolocations because of the inherent elasticity .or 5 give" for whichknitted fabrics are especially noted. As the winding continues, thefabric will narrow at the rolls as well, and the edges of the fabricundergo a decrease in winding tension, resulting in a looserconfiguration or "fault line"-at the corresponding locations in thetubular product. In extreme cases, completed stitches may be under solittle tension as to ride up with the needles as the bed rises, therebyfailing (on a Raschel machine, for example) to clear the latch,whereupon subsequently attempted stitches on the affected needles willbe dropped. The resulting product loss and machine downtime arereflected as a decrease in production and an increase in product cost. 7

Recent developments in Raschel knitting of bifurcated tubular fabricsnot producible on circular-knitting machines have aroused interest ineliminating the mentioned difficulties. It will be apparent that, whenthe bifurcated portions of such tubular fabric are being knitted, thereare twice as many edges to be guided as when a unitary portion thereofis being knitted. This is an additional complication, especially in viewof the necessity of converting from unitary to bifurcated portions andback again as an endless band of bifurcated tubular fabric is soproduced.

A primary object of the present invention is withdrawal of warp-knittubular fabric from the knitting location under essentially even tensionalong the entire warp to and including the edges.

Another object is elimination of necking in warp-knit tubular fabricduring winding thereof.

A further object is accomplishment of the foregoing objects inwarp-knitting of bifurcated tubular garments.

Other objects of this invention, together with means and methods foraccomplishing the various objects, will be apparent from the followingdescription and the accompanying diagrams.

FIG. 1 is a perspective view of a spreading device for use in knittingof tubular fabric according to the present invention;

tion, by maintaining the panels of tubular fabric at essentially theiras-knit width. This is done by guiding them along the inside of theirjoined opposite edges, as by a spreading device of like width insertedtherein to establish guiding loci along opposite edges thereof, a pairof such spreading devices being used for bifurcated tubular fabrics.

FIG. 1 shows spreader plate 11 of this invention in perspective, notdrawn to any particular scale but illustrating the essential featuresthereof. It may be thought of most simply as an originally flatrectangular member whose upper edge 12 has its opposite comers 13, 13rounded and whose lower end has been curved through about one quadrantso as to terminate substantially horizontally and thereby present amodified .l shape in edge view (cf. the next view). The upper portion ofthe body of spreader plate 11 has window 15 formed therein as bystamping. It will be understood that the spreader plate may be formed ofany suitable material (e.g., metal, plastic, ceramic) and in anysuitable manner (e.g., injection molding of plastic material) and thatuse of procedural terms to describe the configuration thereof is merelyfor convenience and not limitative.

FIG. 2 shows spreader plate 11 of FIG. 1 in place between the relevantcomponents of a Raschel machine, forexample, other conventional parts ofwhich are omitted in the interest of simplicity and clarity ofillustration. The components of the upper and lower portions of thispartly sectional side elevation are shown in like view on an enlargedscale in FIGS. 3 and 4, respectively.

Spreader plate 11 fits between parallel trick plates 21 and v 22, withits horizontal top edge 12 substantially flush with FIG. 2 is adiagrammatic edge elevation, partly in section, of

the spreading device of FIG. 1 in use according to this invention;

FIG. 3 is an enlarged detail of components from the upper portion ofFIG. 2;

FIG. 4 is an enlarged detail of components from the lower portion ofFIG. 2;

FIG. 5 is a face elevation, partly cut away, of a plurality of thespreading devices of FIG. 1 in use in the unitary portion of abifurcated warp-knit fabric; and

FIG. 6 is a view similar to FIG. 5 but with the plurality of spreadingdevices in respective bifurcated portions of such fabric.

In general, the objects of the present invention are accomplished, inwarp-knitting of tubular fabric in the form of two closely spaced equalwidth parallel panels knitted together along their opposite edges, whichare withdrawn from the knitting location upon being wound in flatas-knit configuratheir top edges over which panels 10a and 10b oftubular fabric are withdrawn as they are formed by knitting ontorespective rows of needles 25, 26 (only one needle visible in each row)carried on alternately reciprocating needlebeds 23 and 24, which ride upand down along the adjacent surfaces of the respective trick plates.Window 15 in the spreader plate reduces its weight and facilitatesvisual inspection of the fabric.

Respective panels 10a and 10b of tubular fabric are withdrawn downwardbetween the corresponding faces of spreader plate 11 and theadjacent'faces of trick plates 21 and 22 by surface contact with rolls31, 32, and 33 (in that order), all of which have horizontal axesparalleling one another and the needlebeds and trick plates. Largerolls-31 and 33, both of which are usually driven (at the same surfacespeed), are mounted in over-and-under configuration spaced slightly fromone another, and with smaller pinch roll 32, which is usually an idler,intervening at one side to form a nip with each of the large rolls.Curved end 14 of the spreader plate lies adjacent part of first roll 31and terminates between it and third roll 33. Fabric panel 10a passes insurface contact with large rolls 31 and 33 and fabric panel 10b passesin contact with pinch roll 32.

Spreader plate 11 is inserted into the tubular fabric having panels 10aand 10b (and interconnected edges not visible in FIGS. 2 to 4) in anysuitable manner at startup, after which it is retained in place untilsuch time as removal is desired. Thus, it may be inserted in the leadingend of fiat tubular fabric (like a hand into a sleeve) and the end thenbepulled between the rolls, suitably spaced or freewheeling for theoccasion, until the fabric is taut, withthe spreader plate in place.Altematively, and perhaps more commonly, the fabric may be fed betweenthe rolls first and then be slit along one edge to admit the spreaderplate from the side. Once in place, the spreader plate is supported by"lower roll 33, upon which its curved lower end 14 rests (with fabricintervening) so long as the fabric is taut enough from the knittinglocation to the winding location to keep that lower end of the spreaderplate from backing out.

The length of such spreader plate is determined by the distance from thetrick plates to the rolls, and difi'erent machines may require plates ofdifferent lengths, as the level of the lower end of the spreader plateis determined by the lo cation of the winding rolls, and the top edge ofthe spreader plate should extend well up between the trick plates andpreferably substantially flush with the top edges thereof, The width ofsuch spreader plate is determined by the as-knit width of the tubularfabric and should not be any more and not much less than that. Therounded top edges facilitate smooth movement of the tubular fabric ontothe spreader plate in spite of the tendency of the fabric to contractlaterally or neck as it is withdrawn from the knitting location.

The only lateral constraint upon spreader plate 11 is provided by theadjacent edges of the tubular fabric guided thereby. This feature andthe rounding of the top corners of the spreader plate are especiallyimportant in the knitting of bifurcated tubular fabrics, which can beproduced readily in seamless form on the Fashion Master" Raschel machinedescribed in Diehl and Titone Pat. application Ser. No. 759,587, filedSept. l3 l968 based upon earlier Diehl and Titone patent applications,and available from Cocker Machine and Foundry Company of Gastonia, NC.

FIGS. 5 and 6 show a pair of spreader plates 11, 11" like spreader plate11 being used according to this invention in the warp-knitting ofbifurcated tubular fabric, of which one panel is cut entirely away toreveal the spreader plates inside.

In FIG. 5 the spreader plates are inside the unitary portion of thebifurcated fabric (corresponding to the trunk portion of panty hose, forexample) of which only panel 10b is visible, from edge to edge. Althoughshown spaced slightly therefrom for clarity of illustration, the leftedge of left spreader plate is guiding the left edge of the fabric, andthe right edge of right spreader plate 11" is guiding the right edge ofthe fabric. The combined width of the two spreader plates, whoseadjacent edges are actually held contiguous with one another by thetendency of the fabric to contract laterally, approaches the asknitwidth of the fabric to maintain the fabric at essentially its as-knitwidth. The downward direction of travel of the fabric with respect tothe spreader plates is indicated by an arrow superimposed at the top ofthe view, in the vicinity of bifurcation C of the fabric (correspondingto the crotch portion of panty hose, for example). As the fabriccontinues to move downward, bifurcation C enters between the adjacentrounded edges of the respective spreader plates and forces them apartslightly, just enough for the two adjacent edges of the bifurcatedportions (corresponding to the leg portions of panty hose) to passbetween them, as shown in the next view.

in FIG. 6 spreader plates ll and II" are spaced-apart by the adjacentedges of the respective tubular bifurcated fabric portions, being guidedby the right edge of left spacer plate ll and the left edge of rightspacer plate 11", as indicated by D (for division spacing) therebetween.The actualdivision spacing is slight, whereupon the increased spacing ofthe outer most edges of the fabric, still being guided by the same edgesof the spreader plates, is correspondingly only slightly different fromwhat it was in the unitary fabric portion. Each bifurcated tubularportion is maintained at essentially its asknit width by an individualspreader plate just as the unitary portion was kept at essentially itsas-knit width by the two spreader plates together side by side. Soguided, the tubular fabric being knit, whether as unitary or bifurcatedportions, is subjected to essentially unifonn tension from edge to edgeas it is withdrawn from the knitting location, thereby precludingintroduction of undesirable stitch irregularities attributable to unevendrawoff or takeup tension.

It will be apparent, of course, that spreader plates or equivalentspreading means according to this invention are similarly suitable foruse in warp-knitting of tubular fabrics having other configurations thansimple unitary or bifurcated. Thus, trifurcated fabrics can be madesimilarly by use of three such spreader plates, and more plates wouldaccommodate furcate fabrics having more numerous conversions in numberof tubular portions, such as from one to four or four to one, or fromtwo to four or four to two, or from one to two to four to two to one,etc. Double or further multiples of tubes joined laterally along theirlength in Siamese-twin fashion can be provided with individual spreaderplates for each side-by-side tubular portion thereof.

In addition to hosiery and panty hose, therefore, this invention isapplicable in the manufacture of leotards, sweaters, and similargarments, and to industrial fabrics whether unitary. twin, triplet,etc., or bifurcated, trifurcated, etc. Of course, spreader plates ofdifferent widths will be used for tubular portions of unequal size.

The foregoing description and accompanying illustration of methods andmeans for practicing this invention are by way of example rather thanlimitation of the invention, which itself is defined in the followingclaims.

lclaim:

1. ln Raschel knitting of selvagelcss bifurcated tubular fabriccomprising a wide unitary tubular portion and a pair of narrowside-by-side tubular portions joined end-to-end to the unitary portionwherein the tubular fabric is withdrawn from the knitting location bywinding the same in as-knit configuration, the improvement comprisingmaintaining each of the tubular portions there of at essentially itsfull as-knit width by guiding thereof at loci along the opposite insideedges of each such portion as it is withdrawn from the knittinglocation.

2. Raschel knitting of bifurcated tubular fabric according to claim 1,including guiding adjacent edges of the respecting narrow tubular fabricportions at loci along their respective closest adjacent inside surfacesand spaced-apart by a distance substantially equal to the two fabricthicknesses thereof intervening, one such thickness of each such narrowtubular fabric portion being included.

3. Raschel knitting of bifurcated tubular fabric according to claim 2,including guiding the laterally outermost edges thereof at loci alongtheir respective inside surfaces, the lastmentioned guiding loci beingspaced further laterally outward when knitting the pair of narrowside-by-side portions than when knitting a wide unitary tubular portionby a distance equal to the spacing apart of the guiding loci along theinside of adjacent edges of the bifurcated portions from one another.

4. In a warp knitting machine having a pair of parallel needlebedsuseful for knitting tubular fabric thereon and having rolls for windingthe tubular fabric in fiat as-knit form, the improvement comprising flatspreading means having opposite lateral edges thereof spaced-apart adistance approaching the as-knit width of the tubular fabric and adaptedto fit therein and thereby maintain the opposite inside edges so spaced,wherein the spreading means extends from between the needlebeds to thewinding rolls and wherein one end of the spreading means abuts the rollsand is supported thereby, and wherein a pair of the winding rolls havetheir axes essentially horizontal, with one such axis below and parallelto the other and the needlebeds, and the end of the spreading meansabutting the rolls is curved through substantially a quarter circle andextends between the rolls.

5. Knitting machine according to claim 4, comprising a plu rality ofsuch spreading means arranged side-by-side.

6. Knitting machine according to claim 5, wherein the spreading meansare movable laterally along the needlebeds.

7. In a double needlebed Raschel machine for knitting panty hose orsimilar bifurcated tubular garment fabric and having takedown rollsbelow the needlebeds to aid in withdrawing the knit fabric therefrom,the improvement comprising a pair of like spreader plates supportedside-by-side, with their upper ends extending between the respectiveneedlebeds and with their lower ends supported by at least one of thetakedown rolls for withdrawing the fabric in fiat as-knit form about thespreader plates from between the needlebeds, the spreader plates beingsupported thereby for movement laterally along the needlebeds and theroll axes.

8. Knitting machine according to claim 7, wherein the opposite cornersof the upper edge of each spreader plate are rounded to assist entrythereof within the tubular fabric, thereby accommodating the crotchportion between adjacent edges of adjacent plates as well asaccommodating the outer edges of bifurcated and unitary tubular portionsalong the opposite edges of single plates and of two adjacent plates,respectively. a

9. Knitting machine according to claim 7, wherein each spreader platehas a generally J shape as viewed laterally in the plane of the spreaderplate.

. l0. Knitting machine according to claim 7, wherein each spreader platehas a window therethrough.

, below the spreader plates, and supporting the lower end thereof.

13. Apparatus according to claim 11, including a pair of trick plateslocated between the needlebeds and spaced-apart from one another forwithdrawal of knit fabric therebetween, wherein the upper ends of thespreader plates terminate therebetween in position to enterthe fabricand maintain the as'knit width thereof. v

14. Apparatus according to claim 11, wherein adjacent upper comers ofadjacent plates flare outwardly fromone another to facilitate entry ofadjacent thicknesses of furcate portions of the fabric therebetween.

15. In warp knitting of seamless-furcate tubular fabric comprising awide unitary tubular portion and a plurality of narrow side-by-sidetubular portions joined at adjacent ends of each to an end of theunitary portion, the improvement comprising guiding each such tubularportion along opposite inside edges thereof and thereby maintaining itat essentially its full as-knit width from knitting to windinglocations, and winding the guided fabric from the knitting location.

16. Warp knitting and winding according to claim 15, including effectingan interchanging between guiding of the edges of the wide unitarytubular portion and guiding of the edges of each of the plurality ofnarrow tubular portions each time the number of such portions widthwiseof the tubular fabric changes. 1

l7. Warp knitting and winding according to claim 16, wherein theinterchanging is effected by action of the winding fabric itself in thatthe furcate tubular portions space individual guiding locations for theadjacent inside edges of adjacent portions by a distance equivalent to adouble thickness of the fabric, and the unitary tubular portioneliminates such spacing, whereupon the guiding of the inside edges ofthe laterally outermost sides of the fabric undergoes at each suchinterchanging a spacing differential totaling the double thickness timesthe number of locations at which individual side-by-side furcateportions are adjacent one another.

1. In Raschel knitting of selvageless bifurcated tubular fabriccomprising a wide unitary tubular portion and a pair of narrowside-by-side tubular portions joined end-to-end to the unitary portionwherein the tubular fabric is withdrawn from the knitting location bywinding the same in as-knit configuration, the improvement comprisingmaintaining each of the tubular portions there of at essentially itsfull as-knit width by guiding thereof at loci along the opposite insideedges of each such portion as it is withdrawn from the knittinglocation.
 2. Raschel knitting of bifurcated tubular fabric according toclaim 1, including guiding adjacent edges of the respecting narrowtubular fabric portions at loci along their respective closest adjacentinside surfaces and spaced-apart by a distance substantially equal tothe two fabric thicknesses thereof intervening, one such thickness ofeach such narrow tubular fabric portion being included.
 3. Raschelknitting of bifurcated tubular fabric according to claim 2, includingguiding the laterally outermost edges thereof at loci along theirrespective inside surfaces, the last-mentioned guiding loci being spacedfurther laterally outward when knitting the pair of narrow side-by-sideportions than when knitting a wide unitary tubular portion by a distanceequal to the spacing apart of the guiding loci along the inside ofadjacent edges of the bifurcated portIons from one another.
 4. In a warpknitting machine having a pair of parallel needlebeds useful forknitting tubular fabric thereon and having rolls for winding the tubularfabric in flat as-knit form, the improvement comprising flat spreadingmeans having opposite lateral edges thereof spaced-apart a distanceapproaching the as-knit width of the tubular fabric and adapted to fittherein and thereby maintain the opposite inside edges so spaced,wherein the spreading means extends from between the needlebeds to thewinding rolls and wherein one end of the spreading means abuts the rollsand is supported thereby, and wherein a pair of the winding rolls havetheir axes essentially horizontal, with one such axis below and parallelto the other and the needlebeds, and the end of the spreading meansabutting the rolls is curved through substantially a quarter circle andextends between the rolls.
 5. Knitting machine according to claim 4,comprising a plurality of such spreading means arranged side-by-side. 6.Knitting machine according to claim 5, wherein the spreading means aremovable laterally along the needlebeds.
 7. In a double needlebed Raschelmachine for knitting panty hose or similar bifurcated tubular garmentfabric and having takedown rolls below the needlebeds to aid inwithdrawing the knit fabric therefrom, the improvement comprising a pairof like spreader plates supported side-by-side, with their upper endsextending between the respective needlebeds and with their lower endssupported by at least one of the takedown rolls for withdrawing thefabric in flat as-knit form about the spreader plates from between theneedlebeds, the spreader plates being supported thereby for movementlaterally along the needlebeds and the roll axes.
 8. Knitting machineaccording to claim 7, wherein the opposite corners of the upper edge ofeach spreader plate are rounded to assist entry thereof within thetubular fabric, thereby accommodating the crotch portion betweenadjacent edges of adjacent plates as well as accommodating the outeredges of bifurcated and unitary tubular portions along the oppositeedges of single plates and of two adjacent plates, respectively. 9.Knitting machine according to claim 7, wherein each spreader plate has agenerally J shape as viewed laterally in the plane of the spreaderplate.
 10. Knitting machine according to claim 7, wherein each spreaderplate has a window therethrough.
 11. In a double needlebed Raschelmachine adapted to knit seamless tubular fabric having alternatingunitary and furcate portions thereof, the improvement comprising aplurality of spreader plates whose combined widths total substantiallythe as-knit width of the unitary portion and whose individual widthscorrespond to substantially the as-knit widths of the respective furcateportions thereof, the spreader plates being supported side-by-side forlateral movement into and out of mutual contiguity.
 12. Apparatusaccording to claim 11, including at least one roll useful in withdrawalof fabric knitted thereon, located below the spreader plates, andsupporting the lower end thereof.
 13. Apparatus according to claim 11,including a pair of trick plates located between the needlebeds andspaced-apart from one another for withdrawal of knit fabrictherebetween, wherein the upper ends of the spreader plates terminatetherebetween in position to enter the fabric and maintain the as-knitwidth thereof.
 14. Apparatus according to claim 11, wherein adjacentupper corners of adjacent plates flare outwardly from one another tofacilitate entry of adjacent thicknesses of furcate portions of thefabric therebetween.
 15. In warp knitting of seamless furcate tubularfabric comprising a wide unitary tubular portion and a plurality ofnarrow side-by-side tubular portions joined at adjacent ends of each toan end of the unitary portion, the improvement comprising guiding eachsuch tubular portion along opposite inside edges thereof and therebymaintaIning it at essentially its full as-knit width from knitting towinding locations, and winding the guided fabric from the knittinglocation.
 16. Warp knitting and winding according to claim 15, includingeffecting an interchanging between guiding of the edges of the wideunitary tubular portion and guiding of the edges of each of theplurality of narrow tubular portions each time the number of suchportions widthwise of the tubular fabric changes.
 17. Warp knitting andwinding according to claim 16, wherein the interchanging is effected byaction of the winding fabric itself in that the furcate tubular portionsspace individual guiding locations for the adjacent inside edges ofadjacent portions by a distance equivalent to a double thickness of thefabric, and the unitary tubular portion eliminates such spacing,whereupon the guiding of the inside edges of the laterally outermostsides of the fabric undergoes at each such interchanging a spacingdifferential totaling the double thickness times the number of locationsat which individual side-by-side furcate portions are adjacent oneanother.